Colorectal Cancer Awareness Month 2026: Rising in the Young, Falling in Older Adults

Colorectal Cancer Falls in Older Adults, Rises in Younger Adults

One of the most concerning developments in colorectal cancer is the rising incidence among younger adults. 

According to colorectalcancer.org, an alarming 75% of young patients are diagnosed at an advanced stage. And the survival rate for metastatic colorectal cancer is just 13%. As a result, colorectal cancer has become the leading cause of cancer death in individuals under the age of 50, and the second deadliest cancer overall.

According to a recent report from the American Cancer Society (ACS), while colorectal cancer continues to decline among older adults, rates are rising in individuals under 65, particularly among younger adults.

Incidence rates in adults aged 20 to 49 are rising by approximately 3% per year, and nearly 45% of new cases now occur in individuals under 65, compared to just 27% in 1995.

The report found that the increase is mostly being driven by cancers in the distal colon and the rectum. Rectal cancer now accounts for one‑third (32% up from 27% in the mid‐2000s) of all colorectal cancer diagnoses. 

Even more concerning is that three in four colorectal cancers in adults under the age of 50 years are advanced stage (regional or distant) at diagnosis, with just over one in four (27%) distant stage.

The rise in colorectal cancer among younger adults is likely driven by a combination of lifestyle, environmental and biological factors rather than a single cause. Researchers point to a “birth cohort effect,” where people born after 1980 face a higher risk due to early-life exposures. 

Diets high in ultra-processed foods and low in fiber, along with increasing rates of obesity, contribute to chronic inflammation and metabolic changes that can promote cancer. Disruptions to the gut microbiome, linked to diet, antibiotic use and environmental exposures, may also play a role, with certain bacteria associated with tumor development. 

A recent study on geographic and age variations in mutational processes in colorectal cancer found that early-onset colorectal cancers carry distinct DNA mutation patterns linked to exposure to colibactin, a toxin produced by certain gut bacteria. These mutations are significantly more common in younger patients and appear early in tumor development. In addition, the study showed that these mutation signatures vary across countries and are more prevalent in regions with higher colorectal cancer rates, reinforcing the idea that environmental or microbial exposures, rather than genetics alone, are contributing to global and age-related differences in disease risk.

Sedentary behavior, alcohol use and other lifestyle factors further increase the risk of colorectal cancer, while emerging research is exploring the impact of pollutants and chemicals. 

At the same time, delayed diagnosis remains an issue, as younger adults are less likely to be screened and symptoms are often overlooked. Together, these factors are reshaping colorectal cancer trends and driving a shift toward earlier screening and new prevention strategies.

Accelerate Hematological Malignancy Drug Development with MRD and AI

Colorectal Cancer Screening and Prevention

Colorectal cancer is unique among major cancers in that it is highly preventable through screening. Colonoscopy and stool-based tests can detect and remove precancerous polyps before they progress.

However, screening uptake remains suboptimal. More than one in three US adults aged 45 and older are not screened as recommended, despite clear evidence that screening reduces both incidence and mortality.

Long-term population data show that screening programs can reduce colorectal cancer incidence by up to 30% and mortality by as much as 50%, underscoring the impact of early detection.

Standard of Care: From Chemotherapy to Precision Oncology

Historically, colorectal cancer treatment has relied on chemotherapy regimens such as FOLFOX (folinic acid [leucovorin], fluorouracil [5-FU] and oxaliplatin) and FOLFIRI (folinic acid [leucovorin], fluorouracil [5-FU] and irinotecan). While these cytotoxic backbones remain foundational, the treatment paradigm has increasingly shifted toward biomarker-driven precision medicine approaches.

Modern treatment strategies now incorporate targeted therapies and immunotherapies based on tumor genetics, including KRAS, BRAF and microsatellite instability (MSI) status. This shift has transformed colorectal cancer into a highly segmented market, with treatment decisions increasingly guided by molecular diagnostics.

New and Emerging Therapies for Colorectal Cancer

KRAS mutations are present in approximately 40% of colorectal cancers and were long considered undruggable. Recent advances have changed that view.

Amgen’s KRAS G12C inhibitor Lumakras (sotorasib) in combination with the EGFR inhibitor Vectibix (panitumumab) was approved in January 2025, demonstrating improved outcomes in previously treated metastatic CRC. Clinical data show that the combination improved progression-free survival to 5.6 months compared to about 2 months with standard therapy.

The combo of Bristol Myers Squibb’s Krazati (adagrasib) and Eli Lilly’s Erbitux (cetuximab) was approved in 2024 for KRAS G12C-mutated colorectal cancer. The pairing has been shown to achieve an overall response rate (ORR) of 34%, with a median duration of response (DOR) of 5.8 months.

Immunotherapy has significantly improved outcomes for patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) colorectal cancer, which accounts for roughly 15% of cases.

Checkpoint inhibitors such as PD-1 inhibitors like Merck’s oncology blockbuster Keytruda (pembrolizumab) can produce durable responses and long-term survival in these patients. However, the majority of colorectal cancers are microsatellite stable and do not respond well to current immunotherapies, highlighting a major unmet need.